The departure of crew chief Steve Letarte after the 2014 season is one that should worry Dale Earnhardt Jr. fans.

Some fans might want to celebrate his leaving because of just one win in three seasons. They might think that Letarte has taken Earnhardt as far as he could take him — he has turned him into a top-10 driver but not one who can win enough to challenge for the Sprint Cup championship.

Dale Earnhardt Jr. and crew chief Steve Letarte (AP Photo)

But the last nine races of 2013 show just how far Earnhardt and Letarte have come. With six top-six finishes, including three runner-up finishes, in those races, Earnhardt is getting closer and closer to winning. He led laps in 10 of the final 14 races of 2013. He had led in only five of the first 22.

All that progress shows that 2014 could be a great year for Earnhardt, one where he is more of a factor to win races than he was for much of 2013. If his team gets a good handle on the 2014 aero package, it would be easy to see him win two or three races.

Earnhardt has confidence that Letarte can make his car work for him on any weekend. He doesn't have to tell Letarte what to do to the car. He just tells Letarte what is wrong and lets Letarte do the rest.

That's a big difference than Earnhardt's relationships with his last two crew chiefs. He had that kind of chemistry with Tony Eury Jr. for a while but not for their final year together. And he never had it with Lance McGrew.

Earnhardt has been a driver with fragile confidence — confidence that could be shattered after just a few bad races. Getting out of a funk has been a problem for him when he doesn't have the trust in his crew chief to make the right changes. That has led to arguments on the radio, with Earnhardt more interested in arguing with the crew chief than giving the feedback needed to make the car better.

Letarte and Earnhardt don't argue like that. They might have a spirited conversation occasionally, but it is obvious the respect remains.

Earnhardt will need a crew chief with similar abilities as Letarte. He will need a crew chief who knows the car. He will need a crew chief that demands Earnhardt continue to take notes after race weekends. He will need a crew chief not afraid of the Earnhardt presence and thick-skinned enough to bear the brunt of the blame if Earnhardt doesn't perform.

That probably means Earnhardt's next crew chief should have Cup crew chief experience (remember the failed experiment in his pairing with Pete Rondeau several years ago?), someone who is used to calling Cup races and someone organized enough to get the most out of a car.

It can't be an engineer with no personality. It can't be an engineer who believes more in engineering than what the driver is saying. It needs to be someone who recognizes that a driver's feel is more important than what the data says he should feel.

His next crew chief needs to be somebody who is having fun at the job and exudes that type of enthusiasm. It needs to be somebody who can be a cheerleader when needed. It needs to be somebody comfortable in the public eye and comfortable speaking to the media. With Earnhardt as the sport's most popular driver, every decision his crew chief makes will receive more scrutiny than any other crew chief in the sport.

Letarte was the perfect fit. A young and determined crew chief without a huge ego who could handle the attention as well as Earnhardt Jr.'s need for direction and some coaching.

Earnhardt probably has learned from Letarte and maybe can handle a different style of crew chief better than he could have earlier in this career.

But chemistry with a crew chief appears to play a bigger role in Earnhardt's success than it does with other drivers. Finding another crew chief with Letarte's qualities won't be easy, and Earnhardt fans have every reason to be concerned as they think about 2015.